Theorie-Palaver

Institut für Physik

Dienstag, den 30.10.2018
um 14:30 Uhr s.t. im MITP seminar room

Electroweak Baryogenesis and Dark Matter from a Complex Singlet Scalar

Da Huang, University of Warsaw

We connect the electroweak (EW) baryogenesis and the dark matter
physics in a complex singlet scalar S extension of the Standard Model.
We impose the additional CP and Z_2 symmetries on the scalar
potential. With the complex vacuum expectation value of S at the
temperature higher than the EW phase transition, the CP symmetry is
spontaneously broken and a strong first-order EW phase transition is
easily realized. Together with a dimension-6 effective operator that
gives new complex contributions to the top quark mass, we show that it
is easy to yield the observed baryon asymmetry in our Universe. On the
other hand, the CP and Z_2 symmetries are recovered after the EW phase
transition. The lighter real state in S can be the dark matter
candidate, and the strong constraints of CP violations can be avoided.
With the scan of parameter space, we can find models which can explain
the dark matter relic abundance and the baryon asymmetry
simultaneously while satisfying all constraints.